This post follows basic with a variety of Alternate Inference Chains. It is an opportunity to compare their effects and corresponding Sysudoku labeling.
Three bypass clues, naked triple eliminations, and the line slinks marked in cell corners, that’s the outcome from Sysudoku Basic.
The line marked grid:
Sudokuwiki leads off with a 6 – ANL, a 6-chain almost nice loop. The victims sees the two terminals, one of which has to be true. The diamond marks the victim, and I don’t draw in the two weak links.
Then what Sudokuwiki calls a digit forcing chain, I call a boomerang from 1r7c9, and returning to wink into the starting cell, removing its target. Beeby calls it a discontinuous loop, meaning the strong /weak alternation is broken at one candidate of the loop.
The boomer is a form of almost nice loop, in which one closing wink is an internal wink in the return cell. This ANL is a boomer, but one returning to the starting bent region, not the starting cell.
Next in UHC 397 is an ANL with groups at both terminals. One group is a value set of the ALS 167 in r8c47. The victim sees the value set edge on, and shares the box with the other group.
Now we get two boomers from 5r6c4, one branching off the other, to hit two candidates in the same cell.
The grouped boomer removing 6r9c9 is an extension of a 1-way removing 3r9c3 and 7r9c9.
With Sudokuwiki running out of moves and Beeby finding nothing simpler, a long complex 1-way keeps it going.
Starting at 3r8c1, a branch wink removes 6r8c7 to enable an internal slink for a long, grouped complex 1-way We’ll go from there next time, unless you can find a simpler way to bypass the 1-way.
We’ll go from there next time, unless you can find a simpler way to bypass the 1-way.
Systematic Sudoku 